Jeremy85

Hey guys,
Both of the third gens I'm considering buying have TPI 305s with automatics,
and I realize I could nitrous or turbo a 305 to my goal of 500 HP, but it seems to me, and correct me if I'm wrong, that unless the engine has never been touched, a lot of the smog widgets are no longer available, and the best-case tuning scenario still requires a lot of PROM chips.
Is this why the LS1 computer swap is becoming a thing? And does that offer any advantages over an entire LS engine swap?
Non-emissions TPI wiring harnesses might solve it, but I'd rather build my own than spend hundreds extra, if there are any schematics available. Are there? Link, please?

BOTTLEDZ28

iTrader: (9)

You dont need a non emissions TPI harness after you remove the emission equipment from a TPI engine. I removed all my emissions stuff over the summer and had a member here burn me a new memcal. Most of the retune focuses on the deletion of the EGR.

The equipment I removed from my car was the smog pump, cats and EGR. I also installed non A.I.R headers.

Abubaca

iTrader: (3)

I'm a TPI guy. I've always loved the heritage of these cars, and I knew I wanted one long before I could drive. To me, the TPI is just part of what my Iroc is supposed to look like. I built my current 383 with a modded TPI, because I just HAD to keep the TPI. The car is part of the family.

That being said, if I ever got ANOTHER thirdgen, I'd ditch the TPI in a heartbeat and go LS.

Abubaca

iTrader: (3)

As for parts, tuning, engine management software, power etc etc., you're really opening Pandora's box. It's such an in depth conversation with so many variables it'll make your head spin.

With a power goal of 500hp, I think a lot depends on your DIY ability/knowledge, and your budget. I chose a fairly expensive Holley EFI system to run my motor because it came with a pre-built harness, brand new ECU and software, warranty, had some self tuning ability but also the user friendliness to allow me to learn and tune on my own. On top of that, it's supported by a VERY active forum and as a last resort, every major speed shop around will tune it if I need have a professional look at it. Not saying it's the best, and it sure wasn't cheap. ...but it did what I needed. If you have some tuning knowledge and are comfortable with some wiring, talk to RBob here on TGO and Dynamic EFI / EBL. Awesome what he's doing, and what the system can do, and very affordable. I actually purchased it originally, but ultimately felt I needed a little more hand holding as a tuning newbie. ....and of course there's everything in between, other aftermarket set ups, Moates hardware for stock ECMs, LS computers, etc. etc. etc.

Drew

iTrader: (58)

305s aren't worth the hassle. TPI only makes sense if it's a collectible car. If you're going to mod it, chop it, whatever you might as well start with a roller that's already been modded and chopped or a 6er because you're going to replace everything anyway.

Let me put it this way... I've got at least three TPI setups on the shelf, almost all the parts to make it a bolt in deal into my parts car. I'm a big fan of TPI, and I'm still keeping my eyes open for a LS1 donor car, and weighing the possibility of a 4bbl because either option would make it easier to make power than TPI. Not to say that TPI doesn't have it's value, it's just more difficult than the alternatives.

Orr89RocZ

iTrader: (20)

Not sure what you are concerned about with the emissions widgets? Yes to retain emissions, you'd need to buy a car thats never been hacked apart. Pretty rare stuff.
If you dont need emissions devices, then delete them. Cant cut the plugs off the harness to make it neat looking. Or leave them. Dont matter

If you are going to keep a tpi based car you will need to plan on learning how to tune yourself or switch operating systems. Thats a major issue with these cars. Nothing wrong with burning chips but modern flashable efi stuff is much easier and nicer

Lastly, a 305 tpi with a turbo or blower can make the power easily. But you should consider 2 things: should look into stronger valvesprings and pushrods. Also possibly fresh head gaskets lol

After that, boost away and make the power. A well designed turbo system or blower kit can retain emissions devices.

For a front turbo, relocate the battery to trunk to make room for it. Or do what i did and make a rear turbo system. Its gots its own issues to deal with but can work very well

In the end, a good cammed 6.0 lsx swap would be fantastic for the power and dollar invested. Proper ls swaps dont devalue a thirdgen imo lol everyone wants an lsx

alan91z28

what tpi intake manifold are you running on your 383?

Abubaca

iTrader: (3)

It's a heavily ported GM base manifold, SLP runners that have been cut open, ported, and rewelded, hogged out plenum, and of course everything has been port matched.

jmd

iTrader: (4)

I went from L69 to cammed L69 to cammed L69 with TPI ( everything from a wrecked car; swap done right ) then pulled the cam ( mismatch to the TPI ) to put a stock one in.

The TPI is disappointing performance-wise. A perfect running 4bbl L69 will pull 25 mpg hey and TPI might beat that by 1mpg. What I was used to was a powerband that exceeded 6000rpm. The powerband of the TPI is a lower range.

Would I do it again, no. Is it a nice setup that is reliable and torquey, yes. My last carbureted car is now gone as of last year. I wouldn't change a proper running 4bbl SBC with the CCC system to TPI. I just can't commit the time to an LS swap. Yet.

TURBOTOMMY

500 HP out of a TPI 350,,,too easy...I know I know tpi is crap,,,old tech,,doesn't work,,well I say B.S..Does it need some help,,hell yeah it does,if I can pull 600HP out of my Grand National how much more easily can I pull 500 out of a SBC..We will see..Ive always been a fan of tpi I believe that's one of the things that distinguish the 3rd gens among the f-body platform..Personally I get tired of hearing about LS swaps,,yeah there easy and cheap,,but like life is there anything worthwhile that's easy and cheap??


Turbochargers are wonderfull little critters,,it doesn't matter if its a 305 355 or 383 because boost is boost..Theres a hellu learning curve that goes along with them,,but damn gentlemen the reward is huge..Ive thrown enough turbos on different motorized vehicles to know that you can easily,,,very easily eclipse power levels people are laying down with typical LS builds..Im not ready to give up on the old school SBC or TPI just yet..What about you-all....

Jeremy85

Wow! So much to think about. I'm not even sure how to respond, so noone take offense.
I did post in the LSx swap section, adding even more food for thought.
This afternoon I'm going to drive one of these, I arranged it yesterday, I'll try to get a short video.
I have driven an LG4 C10, so I know how bad 305s can be, but maybe the TPI in a sporty car will be better.

TURBOTOMMY

Also your not just going "to throw a turbo on it" and start burning up the streets..There's a hellu learning curve with forced induction,,if it were easy everyone would have them under the hood..Grab that Tiger (boost) by the tail you better know what the hell your doing..Get it wrong and the only thing you'll burn up is your engine..


Also don't get caught up in numbers..Ive seriously humbled more than a few street racing that made a hellu lot more power than me..It doesn't matter if theyre making 400-500-600hp if they cant hook it on the street,,ima take there money..The look on a guys face when he gets his *** whooped by a v6 after he talks so much **** in front of everybody,,,,,is freakin priceless..He was driving a GT500 with a claimed 600hp..Or one of your own buddies that runs a 10teen car at the track,,,but again,,cant hook it up on the street..What happens,,,he goes down in a street race...Don't get hung up on numbers

TURBOTOMMY

In my personal exp. 400hp is typically what the majority of streets will take with the "typical" street car..Anything more than that,,and your just burning rubber most of the time,,spinning isn't winning..My wifes 11stang 5.0 has more than enough to overpower the street..


Now ask yourself,,how hard is 400hp out of a 350.Its not period,,its been done so many times its just kinda pointless to shoot for a goal that low..Now I like TPI,,ITS FANTASTIC for what it was designed todo,,and it does it well..However me personally I wouldn't build one unless I already planned to go forced induction..At the power levels up to 500 you don't need to spend a gazillion bucks on the engine..Spend the money where it counts,,spend wisely remember your not going to be turning the succr beyond 55-6k..

Jeremy85

I gotta admit, I'm 31, and I'm still a bit prideful. I get a bit butt-hurt when a nice late-model gets around me. But I'm no racer. I cruise at 5 over the posted limit like most everyone else, so I get all self-righteous that noone except police should be able to get past me. Especially not something like a Lexus or Infinity. I've worked my way up out of poverty, but I have a rich in-law with a warmed-over Maserati. He's my first target for any racing, if I can get him to the dragstrip this summer.
I don't need the emissions widgets, but deleting them creates horror stories of driveability problems, so if I do delete them, I want to do it right. I can't see EGR or Air Injection being compatible with boost anyway.
I just posted in the transmission section, I'm going to choose between my 3 options based on which is easiest on a T56; (1) Nitrous 305 TPI (2) Turbo 305 TPI (3) higher-RPM LS

Abubaca

iTrader: (3)

The main thing I've gained from this thread is do NOT race TurboTommy. He will win.

monkey-leader

Its not worth any time. unless youve already screwed up and bought a 3000$ stand alone ecm. FML.

On that, anybody interested in buyin a bnib Accel DFI 7 TPI ECM with wiring harness/power key?

Abubaca

iTrader: (3)

Ya know as much as I love the TPI, I'll be the first to admit that if you're starting from scratch, the TPI isn't the best system to start with.

However....it's not like it's drastically different. On most moddest set ups, you won't ever know the difference. ...and as the engine gets more powerful, you may feel the difference, but only if you were to compare back to back. ...and even then, you often get more low RPM kick in the seat that a lot of people like, unless you're a serious drag race guy or dyno number queen. As TurboTommy said, it's not about the numbers.

As a TPI guy, I don't mind admitting it's shortcomings, but if you think it's crap, or worthless, there was probably something else wrong with your set up.

Jeremy85

Not the best experience. First, I dropped my phone. Then, it took half an hour to get it started. It drove ok, pulled well to 4200, that was the 1-2 upshift with the go pedal in the carpet, then nothing. I lifted, and it found third and we continued, but second gear just was not there at all.
I tossed the car left and right in my lane, jammed the brakes, turned around, and hit every bump I saw. All of that went ok.
It might have been more impressive when new, but a stock 305 TPI isn't strong enough to suit me, so a nitrous build is out. I'd go through a bottle per day. Well, maybe a nitrous TPI 350 build, with more aggressive gearing, that might be a good option?

cuisinartvette

500 from a tpi 305 hope you arent on a budget
Go for cubes and a better intake youll thank yourself later.

jharrison5

I was in the process of doing a LS swap into my '87, but switched directions and went with a '98 vortec 350. I'm running a MAP tpi setup on it with the help of a new base, and the management is a FAST EZ EFI 2.0. My factory wiring was shot and when i did the numbers it made more sense to buy a self learning system then to pay for a custom tune.

To each their own but I'm happy with the route my car is going.

brian p

My car started out as a 305 TPI, now an L31 with an HSR and a cam and gears and I'm still, well, slow, in comparison to the new stuff. And nowhere near 500hp. I've spent years gradually changing things, first all the sensors, then the wiring harness, then the throttle body, then the motor underneath everything but it was a long way around and I'm still stuck in the 80's/90's for all intents and purposes. If you want to make some hp, save yourself a whole pile of grief, yank the whole OEM mess out, save it if you want to go original someday, and start with a stroker or a LS. It's gotta be cheaper and quicker (pun intended) in the long run.

Vanilla Ice

If you want fourth gen performance get a fourth gen.

cuisinartvette

Nothing wrong with being "stuck" in that era thats why we like these things
I love carbs grew up with them they have come a long way lots of adjustability
With 02 sensor kits worrying about idle/plug fouling issues are a thing of the past.

bk2life

Simple answer, yes.

eaglesfan534

Save a TPI car! It's like saving a Panda. They are going extinct!

So far, my TPI has been a nightmare to tune, and get running after putting in a 350. I haven't been able to break-in the Flat-Tappet Cam yet....

But when they are running how they are supposed to, and tuned properly, they are a fantastic system! They look extremely Unique under the hood too

Abubaca

iTrader: (3)

The TPI doesn't affect the tune, and a 350 (for tuning purposes) is just a 350. The problem is somewhere else, not the TPI. You could put any other intake on and with the same to tune. ...I mention this only because the title of the thread is questioning if TPI is worth the hassle and it's unfair to suggest that's it's problematic to tune.

bk2life

The first issue I see here, is the OP asked is TPI worth the hassle.
Then he continues and states he has a 500hp goal.
Further he says he wants to race his buddies maserarti
Lastly he has made 3 choices: 1) Nitrous 305 TPI (2) Turbo 305 TPI (3) higher-RPM LS


So here is my point. I feel the OP doesn’t know what he wants, and needs to further his research. He is 31 and like most of us, been bitten by the demon tweak and probably has a few dolalrs burning a hole in his poclet.

Having built a few rides for myself and customers, if horsepower is the main goal, get an LS. No other way around it. I have a customer with a 600+ ci BBC with 40+ thousand dollars into it, and his words exactly “if I did it over it’d be a turbo’d LS”

I myself have a low optioned, 1991 GTA I'm currently doing a mild restore on it. It’ll have a 383/First Intake/all emissions/headers with AIR piping/cammed/blah blah blah, as I want this build to look stock when the hood is opened, and be a great daily driver. IF this car wasn’t a ‘high dollar-low optioned’ vehicle, it would be cut, mini tubbed, 9” rear, 4-linked, and a twin turbo’d LS no questions asked. So is a TPI system worth it? It depends on what you’re doing. 9 second ¼ mile times? No. But cruising to the Super Chevy show in Michigan or going on the Power Tour and you start your trip from Arizona and the entire trip will be about 3500 miles and letting your 16-year-old daughter drive because you are tired? Then yup, worth it.

--every build needs a plan, otherwise you just throw money away.

eaglesfan534

I actually found my problem to be trying to keep the dinosaur 85' computer and trying to burn a working chip for it. I just recently took the time to repin my harness, and swap in an 87' computer, and had a new chip burned. Car fired up first start and idles great. Now I know why everyone told me to ditch my 85' ecu on day one....

86Z

iTrader: (4)

i had an LG4 carbed 305 swapped in an 88 with the carb setup, converted to Tuned Port Injection, utilized an accel base and runners all ported, added a procharger with 14#'s i dyno'd 380hp/420 torque to the wheels, i'm now parting it out because tuning/driveability sucked, got a stock 02 LQ9 LS going in shortly, if i desire more power i'll add a turbo.